Eastern North American Liana Distributions Reveal Conservation and Climate Mitigation Potential

Abstract

Aim

We created the first high-resolution distribution maps for lianas at a continental scale to address critical knowledge gaps in invasive species management, forest carbon storage, and temperate forest ecology.

Location

The Nearctic realm and Eastern North America.

Methods

We developed a cascading modelling approach using Google Earth Engine that first classifies suitable climate envelopes at 5 km resolution across North America, then predicts occupancy within suitable areas at 250 m resolution using remotely sensed data, topography, and soil maps. We modelled four ecologically and economically important lianas capable of enshrouding forest canopies: Oriental bittersweet (Celastrus orbiculatus), kudzu (Pueraria montana), summer grape (Vitis aestivalis), and Chinese wisteria (Wisteria sinensis). These species represent native and nonnative species with contrasting dispersal mechanisms.

Results

Approximately 378.8 $\pm$ 36.4 million hectares are suitable for at least one of the focal species, with 57.9 $\pm$ 8.5 million hectares of forest likely occupied. Native and nonnative lianas exhibit differences in distribution patterns: while all lianas studied here are associated with urbanization and development, this pattern is particularly strong for species with limited seed dispersal (kudzu, wisteria), whereas the native grape and bird-dispersed nonnative bittersweet show broader distributions, challenging widespread assumptions about their climate-driven distributions and ability to spread across landscapes. However, given moderate SDM accuracy and potential sampling biases in presence records, area estimates should be interpreted as indicative rather than definitive.

Main Conclusions

Our computationally efficient cascading approach enables high-resolution species distribution modelling at scales previously prohibitive, particularly for range-restricted or invasive taxa. We demonstrate that urbanization drives nonnative liana distributions, suggesting targeted management strategies. These maps provide immediate conservation applications for invasive species control, urban forest management, and potential carbon sequestration enhancement. Our publicly accessible models and workflow offer a proof-of-concept for functional group mapping applicable to understudied taxa globally.